本产品适用于交流额定电压300/300V及以下电器、仪表、电子设备及自动化装置;本产品采用的标准与国际电工委IEC227(1979)标准规定相一致。 This product is fit for ac rated voltage 300/300v electric appliances.instruments and meters.electro-equipment and antomatic installations.dur standard for this product is based on thestandard made by intemational electric commission IEC227(1979)and is exactly the same.